Prevalence and clinical course of chronic hepatitis C virus (HCV) infection and rate of HCV vertical transmission in a cohort of 15,250 pregnant women

The prevalence and natural course of chronic hepatitis C virus (HCV) infect ion was evaluated in 15,250 consecutive pregnant women. The rate of HCV ver tical and perinatal transmission was also assessed. The presence of anti-HC V was tested by means of EIA III and confirmed by recombinant immunoblot as say III. Alanine transaminase (ALT), anti-human immunodeficiency virus (HIV ), and HCV-RNA were tested during the first month and third trimester of pr egnancy, and 6 months after delivery; the same tests were made in all of th e newborns of anti-HCV-positive mothers at birth (on cord blood samples) an d then at dr-month intervals. Anti-HCV positivity was found in 370 cases (2 .4%), 72% of whom were also HCV-RNA-positive. The proportion of women with hypertransaminases decreased from 56.4% at the first examination during the first month of pregnancy to 7.4% in the last trimester, and then increased again after delivery (54.5%), without any concomitant changes in the propo rtion of those with viremia, The proportion of anti-HCV- and HCV-RNA-positi ve newborns was 5.1% after 1 year (8 of 155), all of whom had the same geno type as their mother. The rate of HCV transmission was not affected by the type of delivery or feeding, or the HIV status of the mother. The results o f this large-scale study confirm previous data in smaller series concerning the prevalence of HCV infection in pregnant women, and strongly support th e hypothesis of a favorable (possibly immunomediated) effect of pregnancy o n liver cell necrosis in anti-HCV-positive women.